usb4_switch_map_usb3_down(9)

📦 version 7.3.1, in nixpkgs unstable

💅 usb4_switch_map_usb3_down

ok so real talk, this is a page from the Kernel API Manual, section 9 (that's the kernel-API section bestie, not "random command you type in ur shell" — big difference ✨). It's the usb4_switch_map_usb3_down(9) page, and honestly? it's short, it's sweet, it's iconic. Let's get into it 🎀

✨ NAME ✨

usb4_switch_map_usb3_down — maps a USB4 port over to a USB3 downstream adapter 🦋

🌸 SYNOPSIS 🌸

struct tb_port * usb4_switch_map_usb3_down (struct tb_switch *sw , const
struct tb_port *port );

💖 ARGUMENTS 💖

  • sw — the USB4 router. that's the whole box, the main character of the operation 👑
  • port — a USB4 port. one (1) single port, the one we're asking about 🫶

⭐ DESCRIPTION ⭐

okay so here's the vibe: USB4 routers keep a direct mapping between their USB4 ports and their USB 3.x downstream adapters — specifically the spots where the USB 3.x topology branches out and keeps going. no cap, it's wired in 🔥

this function does exactly one (1) job and does it slay: it hands you back the corresponding downstream USB 3.x adapter.

and if that mapping just... isn't a thing? if it wasn't possible? you get NULL. no adapter, no problem, no drama 💀

🧚 RETURN 🧚

a pointer to struct tb_port, OR NULL if it wasn't found. that's it, that's the whole return value, periodt 💅

🌈 SEE ALSO 🌈

alright bestie, buckle up, because this list is long — and i mean every single one of these is getting its moment 💖 the kernel file in question is ./drivers/thunderbolt/usb4.c, and the whole squad is:

like i said. every single one. iykyk 🫶

okay that's the whole page, go touch some hardware bestie 💜 this cutie lives in ./drivers/thunderbolt, the manual's dated October 2026, and it's brought to you by the Kernel API Manual — mwah, stan, bye 👑✨🎀

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